Accidental versus new food allergy reactions in a pediatric emergency department

Current perspective on allergen immunotherapy for food allergies

Food allergies are an increasing global problem and societal issue. In addition to the potential for severe allergic reactions from accidental ingestion, food allergies impose a significant burden on the quality of life, nutrition, cost of living, and social activities of both those afflicted and their caregivers. Strict avoidance of allergens and use of emergency medications to treat allergic reactions are the traditional management and treatment strategies; however, significant progress has been made in recent years toward better treatment of food allergies. Many clinical trials on food allergen immunotherapy (oral, epicutaneous, and sublingual) have revealed its efficacy in increasing reaction thresholds and desensitization. These positive results led to the first FDA approval of peanut oral immunotherapy (OIT). However, safer and more effective approaches are required, and adjunct treatments and allergen modifications are being considered. More than 100 facilities in Japan conduct OIT, and numerous studies on it have been reported. Unlike in Europe and the US, stepwise oral food challenges with dietary guidance are conducted separately from the OIT. This review describes the current perspectives on allergen immunotherapy for the treatment of food allergies, focusing on evidence from Japan.

Accidental allergic reactions to immediate-type food allergens in Japanese children: A single-center study

BACKGROUND

Few studies have assessed the nature of accidental allergic reactions (AAR). We assessed the prevalence and risk factors for AAR in Japanese children.

METHODS

This study included children with immediate-type hen's egg (HE), cow's milk (CM), wheat, or peanut allergy who developed allergic reactions within at least 2 years and were followed up regularly at a single national allergy center in Japan. From January to December 2020, low-dose reactivity was defined as allergic reactions to ≤250, ≤102, ≤53, or ≤ 133 mg of HE, CM, wheat, or peanut protein, respectively. The annualized AAR rate showed the number of reactions per patient per year (95% confidence interval). AAR risk factors were analyzed using multiple logistic regression.

RESULTS

Of the 1096 participants, 609, 457, 138, and 90 had HE, CM, wheat, and peanut allergies, respectively. The median (interquartile range) age was 5.0 (2.3-8.6) years, 39% had completely eliminated allergenic food, and 24% had low-dose reactivity. The annualized AAR rate was 0.130 (0.109-0.153) in all sub-cohorts. Moderate and severe symptoms occurred in 50% and 0.7%, respectively, of children who experienced AAR. Multiple logistic regression revealed that low-dose reactivity was a significant risk factor for AAR in the overall and CM cohorts, respectively (p < .001 and p = .036).

CONCLUSION

In this single-center study in Japan, the annualized AAR rate was relatively low during the COVID-19 pandemic; however, half of the participants with AAR had moderate to severe symptoms. Especially in the case of low-dose reactivity, children would require careful AAR risk management.

Peanut-Induced Anaphylaxis in Children: A Literature Review

Peanut allergy has become more common among children and is considered one of the most common triggers for fatal anaphylaxis. Treatment of symptoms during a reaction is only one aspect of managing anaphylaxis; other elements include rigorous dietary avoidance and education about settings that could put the patient at a high risk of unintentional exposure. We aimed to review the prevalence, mechanism, diagnosis, treatment, and emergency action of peanut-induced anaphylaxis among children. We used a web-based literature search using the advanced features of databases such as PubMed, Scopus, Directory of Open Access Journals (DOAJ), Embase, Google Scholar, and Cochrane electronic databases. The most common food to cause fatal anaphylaxis and a common cause of food allergies is peanuts. Over the past two years, our knowledge improved more about peanut allergens, their prevalence, causes, diagnoses, and treatments. The research cited in this review demonstrates that the peanut allergens are most closely associated with disease differ across cultures, that early oral peanut exposure may reduce the occurrence of peanut allergy while early non-oral exposure may have the opposite effect, that complement activation by peanut constituents appears to promote peanut-induced anaphylaxis, and that oral immunotherapy, anti-IgE antibody, and a herbal formulation are all demonstrating promise as treatments. To conclude, peanut allergies have increased frequently during the past 10 years, especially in Westernized nations. Given that peanut allergy poses a danger for fatal anaphylaxis, response management is crucial. The current standard of care for those with nut allergies comprises complete food avoidance and the administration of injectable epinephrine to treat systemic symptoms.

Maillard Reaction Induced Changes in Allergenicity of Food

Food allergy is increasing in prevalence, posing aheavier social and financial burden. At present, there is still no widely accepted treatment for it. Methods to reduce or eliminate the allergenicity of trigger foods are urgently needed. Technological processing contributes to producing some hypoallergenic foods. Among the processing methods, the Maillard reaction (MR) is popular because neither special chemical materials nor sophisticated equipment is needed. MR may affect the allergenicity of proteins by disrupting the conformational epitope, disclosing the hidden epitope, masking the linear epitope, and/or forming a new epitope. Changes in the allergenicity of foods after processing are affected by various factors, such as the characteristics of the allergen, the processing parameters, and the processing matrix, and they are therefore variable and difficult to predict. This paper reviews the effects of MR on the allergenicity of each allergen group from common allergenic foods.

Accidental ingestions to known allergens by food allergic children and adolescents

BACKGROUND

Accidental ingestions (AI) of food allergens in children compared with adolescents with food allergies are poorly characterized. It is suggested that AIs are higher in adolescents than children and that their reactions may be more severe, presumptively due, at least in part, to increased risk-taking behavior. We compared reported AIs in children versus adolescents.

METHODS

An online cross-sectional survey was distributed to parents of children with food allergies via Twitter, food allergy advocacy groups in the UK, South Africa, and Australia, and locally at Children's Hospital Colorado.

RESULTS

Of 558 respondents, 105 were parents of adolescents, and 453 had children <12 years. 73% (341) reported an AI since diagnosis, with 85% of adolescents having had an AI versus 70% of children (p = 0.0058). The annualized rate of AI was significantly lower in the adolescent population at 0.21 versus 0.53 in children (p = <0.0001). Although adolescents reported fewer severe reactions (2% vs. 16%, p = 0.0283), more adolescents required epinephrine administered by a medical professional for their most severe AI, (48% vs. 24%, p = 0.0378). Comparison of the two age groups is limited by the fact that many AIs in the adolescent group occurred prior to age 12. There was no significant difference between the groups as to where the food was consumed or the type of food. There was a significant difference in accidental ingestions in patients in all age groups with more than one reported food allergy; 78% of those with more than one food allergy reported a prior history of at least one accidental ingestion, compared with 59% in those with a single food allergy (p < 0.0001). Regional differences were also noted with respondents in the United States reporting 0.3 accidental ingestions a year, 0.4 in the UK, and 0.5 in other countries (p = 0.0455). The number of reactions was, on average, 27% lower (95% CI: 40, 11%) in the United States compared with the UK (p = 0.0019).

CONCLUSION

The number of severe reactions, and epinephrine need, differs in children compared with adolescents, although many of the reported reactions in both groups occurred before the age of 12. There were also regional differences with the United States reporting a lower number of AIs and less AIs per year than the other participating regions, as well as increased rates of AI in participants with more than one food allergy. Further characterization of the differences in AIs between children and adolescents, as well as between regions, is needed to assist with more patient-centered anticipatory guidance.

Use of multiple epinephrine doses in anaphylaxis: A systematic review and meta-analysis

BACKGROUND

Regulatory bodies recommend that all patients at risk of anaphylaxis be prescribed 2 epinephrine autoinjectors, which they should carry at all times. This is in contrast to some guidelines. The proportion of anaphylaxis reactions that are treated with multiple doses of epinephrine has not been systematically evaluated.

OBJECTIVE

Our aim was to undertake a systematic review and meta-analysis of published studies reporting epinephrine treatment for anaphylaxis in which data relating to the number of doses administered were available.

METHODS

We searched the Medline, Embase, and Cochrane databases for relevant studies reporting at least 10 anaphylaxis events (due to food or venom) from 1946 until January 2020. Data were extracted in duplicate for the meta-analysis, and the risk of bias was assessed. The study was registered under the PROSPERO identifier CRD42017069109.

RESULTS

A total of 86 studies (36,557 anaphylaxis events) met the inclusion criteria (20 of the studies [23%] were prospective studies; 64 [74%] reported reactions in the community, and 22 [26%] included food challenge data). Risk of bias was assessed as low in 50 studies. Overall, 7.7% of anaphylaxis events from any cause (95% CI = 6.4-9.1) were treated with multiple doses of epinephrine. When only epinephrine-treated reactions for which subsequent doses were administered by a health care professional were considered, 11.1% of food-induced reactions (95% CI = 9.4-13.2) and 17.1% of venom-induced reactions (95% CI = 11.3-25.0) were treated with more than 1 epinephrine dose. Heterogeneity was moderate to high in the meta-analyses, but at sensitivity analysis this estimate was not affected by study design or anaphylaxis definition.

CONCLUSION

Around 1 in 10 anaphylaxis reactions are treated with more than 1 dose of epinephrine.

Eosinophilic esophagitis during sublingual and oral allergen immunotherapy

PURPOSE OF REVIEW

The aim of this review is to discuss the current evidence regarding the development of eosinophilic esophagitis (EoE) in individuals undergoing oral and sublingual immunotherapy (SLIT) for both food and environmental allergens. Cumulative incidence of EoE in patients on allergen immunotherapy for peanut, milk, and egg is estimated.

RECENT FINDINGS

De novo development of EoE in patients undergoing oral and SLIT has been demonstrated on the scale of case reports and prospective randomized trials. However, few individuals with EoE-like symptoms during immunotherapy undergo endoscopy, and the long-term outcomes of immunotherapy-associated EoE are unknown.

SUMMARY

Evidence exists to suggest that allergen immunotherapy could place individuals at risk for the development of EoE, the true incidence of which may vary depending on antigen exposure and methods used to define the condition.

Food reactions during avoidance: Focus on peanut

OBJECTIVE

Peanut allergy has historically been difficult to manage, with most cases persisting into adulthood. Novel therapies for peanut allergy treatment are on the horizon, yet allergists must maintain a robust understanding of the risks and benefits of the current standard of therapy, avoidance diet.

DATA SOURCES

A comprehensive literature search using PubMed of reviews and clinical articles was performed.

STUDY SELECTIONS

Articles discussing peanut or other food-related allergic reactions, accidental exposures or anaphylaxis pertinent to avoidance diet or comparative to oral immunotherapy trials were selected.

RESULTS

Peanut remains a leading allergen associated with accidental ingestions responsible for food-related reactions, both mild and severe. Fatal reactions, however, are rare and measures such as anaphylaxis plans can significantly decrease the risk of accidental anaphylaxis. Patients may over estimate situations thought to increase risk for reactions to peanut, such as inhalation or contact through skin. In oral immunotherapy trials, the rate of anaphylaxis secondary to treatment was significantly higher than avoidance practices.

CONCLUSION

Clinicians should continue to discuss avoidance as a viable option for long-term peanut allergy management and empower patients to differentiate relevant situations in which accidental reactions might occur.

Estimation of Health and Economic Benefits of Commercial Peanut Immunotherapy Products: A Cost-effectiveness Analysis

IMPORTANCE

Commercial epicutaneous peanut immunotherapy (EPIT) and peanut oral immunotherapy (POIT) may offer significant quality-of-life improvements for patients with peanut allergy, but the cost-effectiveness of commercial peanut immunotherapies is uncharacterized.

OBJECTIVE

To evaluate critical inputs associated with the cost-effectiveness of EPIT and POIT from a societal perspective.

DESIGN, SETTING, AND PARTICIPANTS

Economic evaluation in which microsimulations with Markov modeling were performed evaluating virtual children aged 4 years over an 80-year time horizon. The base-case costs included a caregiver-reported willingness to pay of $3839 annually for safe and effective food allergy treatment. Estimates of predictive biomarkers or oral challenges were incorporated after the first year of therapy with additional analyses of immunotherapy risk reduction of anaphylaxis and probability of sustained unresponsiveness (SU) to peanut after 4 years.

EXPOSURES

Children received EPIT, POIT, or no immunotherapy treatment (n = 10 000 per treatment strategy).

MAIN OUTCOMES AND MEASURES

Rates of therapy-associated adverse reactions and quality-of-life improvements associated with changes in eliciting or tolerated peanut doses were modeled along with quality-adjusted life-years (QALYs), anaphylaxis, therapy-associated anaphylaxis, and fatalities.

RESULTS

In the base-case analysis without SU to peanut, the EPIT strategy cost less than POIT (mean [SD] cost, $154 662 [$46 716] vs $163 524 [$56 800]) and had fewer total episodes of anaphylaxis (mean [SD], 1.33 [1.55] vs 3.83 [5.02] episodes) and fewer episodes of therapy-associated anaphylaxis (mean [SD], 0.62 [1.30] vs 3.10 [4.94] episodes) but had lower QALY accumulation (mean [SD], 26.932 [2.241] vs 26.945 [2.320] QALYs). The incremental cost-effectiveness ratio was $216 061 for EPIT and $255 431 for POIT. Models were sensitive to therapy cost, SU rates, health state utility, and risk reduction of anaphylaxis. With health state utility sensitivity analyses, the ceiling value-based cost (willingness-to-pay threshold $100 000/QALY) was between $1568 and $6568 for EPIT and between $1235 and $5235 for POIT. If high rates of SU to peanut can be achieved in longer-term models, EPIT and POIT could produce savings in terms of both cost and QALY.

CONCLUSIONS AND RELEVANCE

In this simulated analysis, findings showed that EPIT and POIT may be cost-effective under some assumptions. Further research is needed to understand the degree of health state utility improvement associated with each therapy, degree of protection against anaphylaxis, and rates of SU.